Prélude in E minor

Chopin's twenty-four Préludes were published in 1839, one in each key. The fourth is among the shortest and the most harmonically dense: twenty-six measures over a bass that descends almost entirely by step and half-step, with a chromatic surface that never once dislodges the home key. Its two large sections open with identical material before diverging into something quite different.

The tonal language

E minor holds for the whole Prélude. The single sharp in the signature is never altered, and the piece comes to rest on a root-position tonic. The surface, meanwhile, is as chromatic as anything in the set — and none of that chromaticism is modulation. Secondary dominants colour the subdominant and, later, the mediant; a Neapolitan inflection arrives at the corresponding point in each half. Each resolves back inside E minor rather than establishing a rival centre. The one gesture toward the parallel major is briefer still, a passing brightening late in the second half before the harmony settles back into minor for the approach to the close. The raised leading tone does its defining work exactly once, at the piece's only perfect authentic cadence.

The statement — mm. 0–12

The Prélude opens unaccompanied: a single quarter-note anacrusis, marked p and espressivo, at the Largo that governs the piece entire. The left hand enters only at m. 1, and with it the texture that persists essentially unbroken for the next eleven measures — a three-note chord repeated eight times to the bar beneath a sustained melodic line, sempre legato. The chord's shape scarcely varies. What moves is its position, sinking by step and half-step across the span.

That descent is the structural spine, a fall of a fifth traversed almost entirely stepwise. Two of its way-stations are secondary dominants, tonicizing first the subdominant and then the mediant; between and around them a Neapolitan inflection, a diminished seventh and an augmented triad supply the chromatic colouring characteristic of the piece's language. Against this bass the melody is strikingly static, holding each pitch for three or four measures and moving only by an upper neighbour on the weak half of the bar. That single-note neighbour is the statement's only recurring ornament. The line breaks into rapid motion just once, vaulting under a crescendo to the phrase's ceiling before falling back within the measure.

The two-layer texture dissolves at m. 12. The left hand sounds on the downbeat, then rests, leaving the melody to descend unaccompanied into the cadence. The statement closes on the downbeat of m. 13 with an imperfect authentic cadence — tonic in first inversion, the soprano arriving on the fifth rather than the first. Closure is sounded and withheld in the same gesture. Across these measures the music has occupied the narrowest of the piece's three registral frames.

The intensified restatement — mm. 13–23

The restatement opens as the statement's literal double — the same harmony, the same soprano, the same sonority opening the following measure, unchanged down to the pitch. The correspondence breaks precisely at the second beat of m. 14, where the Neapolitan displaces the dominant seventh that had occupied the equivalent beat earlier. From there the two halves part company. Rather than retracing the fifth-based descent, the music sinks through a lowered supertonic region toward a secondary dominant of the subdominant. What follows is not repetition but accumulation: more notes to the bar, a wider frame, and at m. 16 a written-out turn in thirty-second notes replacing the single-note neighbour that had served as the piece's only ornament until then.

Then m. 17. The bass plunges two octaves to its lowest point so far, landing on the dominant, and the texture thins to a bare octave and a single melodic pitch — the widest span the Prélude reaches, achieved with its sparest sonority. From that hollow arrival the music erupts into its only forte, and an eighth later into its highest note. Registral ceiling, widest simultaneity, sole forte: every parameter in the score corroborates m. 17 independently as the climax. The phrase breaks off there, on the dominant, without resolving.

The second phrase opens directly from the climax and spends its first measures descending from it through a chain of diminished-quality sonorities, touching an augmented harmony that echoes the mediant colouring of the first half before settling briefly on the tonic. A genuine subdominant follows, then a recurring gesture heard several times already — a bare octave standing in for a chord, one voice arriving a step above its goal and resolving down into the harmony below. The dominant that finally arrives at m. 20 is complete and unambiguous, and it resolves deceptively across the barline to the submediant, bass and harmony continuous, with no separation between arrival and evasion. The phrase then dissolves at m. 23 into a single sustained chord followed by a full beat of silence in both hands: the only complete rest in the Prélude, and the restatement's sole means of closing where no cadence is offered.

The coda and close — mm. 24–25

The coda abandons, in a single stroke, the texture that has carried the entire Prélude. The repeated-chord accompaniment gives way to block chords moving in strict rhythmic unison between the hands, each sustained a full beat, marked pianissimo at the end of a diminuendo running since the deceptive resolution. The harmonic rhythm slows to match: where the restatement had changed harmony many times within a single measure, the coda offers three events across two.

The approach chord carries the same suspended quality found repeatedly through the preceding sections — a sonority without its defining third, resolving by a single half-step into a fully formed dominant in root position. From there the harmony resolves, at last without evasion, to a root-position tonic. The melody arrives on the pitch the restatement had already reached before the silence intervened and holds it the length of the measure; beneath it the bass sounds the lowest pitch of the entire piece, reinforced through the octave. Three statements of the tonic across as many octaves bring to rest the chromatic descent that has driven the music since its opening measure.

Formal structure

Cadence map

Two further candidates in the second half are a single elided dominant rather than an independent close. Complete cadence locations, Roman numerals, and scale-degree detail are given in the study guide.

Texture and register

One texture carries almost the entire Prélude: a three-note chord repeated eight times to the bar in the left hand, beneath a melodic line that moves at a fraction of that rate. It is unbroken from m. 1 apart from two brief lapses, and both fall at moments of structural consequence — the unaccompanied descent into the statement's cadence, and the bare octave at the climax. The coda breaks it altogether, substituting block chords in rhythmic unison found nowhere else in the score.

Register traces a matching arch. The statement occupies the narrowest frame of the three spans; the restatement exceeds it at both ends; the coda is narrower again, yet contains the lowest pitch in the work. The structural low points fall progressively across the whole piece — the same harmonic goal reached an octave lower at the climax than in the statement, then the tonic itself at the close. The dynamics do the same thing a third time, from the opening p through the single f to the coda's pp, and the texture a fourth: steady repeated chords, then a bare octave, then block chords.